The Congressional Research Service summarizes the case and its remedies. If you own an affected TDI, keep records of any approved emissions modification. General diesel pages (fuel, glow plugs, EGR, DPF) still apply.
Common to all diesels
These apply to VW TDI engines too.
- Hard start when cold
- Cranks, will not start
- White smoke
- Black smoke
- Blue smoke
- Low power / limp mode
- Rough idle
- Water in fuel light
- Fuel in the oil
- Losing coolant
- DPF and regeneration
- Cold-weather gelling
- DEF / SCR faults
- NOx sensor problems
- Clogged EGR valve
- Turbo whistle / boost leak
- Injector knock
- Glow plug / grid heater failure
- Fuel filter restriction
- Air in the fuel
- Oil consumption
- Crankcase blow-by
- Maintenance basics
- Winter diesel prep
- Buying a used diesel
- Is a DPF/EGR delete legal?
Where this comes from
- Congressional Research Service: Volkswagen, defeat devices and the Clean Air Act
- U.S. EPA: Tampering and aftermarket defeat device enforcement policy
Last reviewed 2026-10-19. General information only: confirm with your service information and a qualified diesel technician.